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US 5,399,325 AGranted
Nitrogen oxides reduction using a urea hydrolysate
AssigneeNalco Fuel Tech
InventorsThure von Harpe, Reinhard Pachaly, M. Linda Lin, Daniel V. Diep, Joseph B. Wegrzyn
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Abstract
The present invention relates to a process for the use of a urea hydrolysate for nitrogen oxides reductions. More particularly, the process involves forming a urea hydrolysate and introducing the hydrolysate into a combustion effluent under conditions effective for the reduction of nitrogen oxides.
Claims10
A process for the reduction of nitrogen oxides in a combustion effluent, the process comprising:
- a) subjecting an aqueous solution of urea to heat and pressure for a time sufficient to hydrolyze at least 5% of said urea to a hydrolysate comprising a complex of ammonium carbamate with ammonium bicarbonate and ammonium carbonate, where the ratio of ammonium carbamate to ammonium bicarbonate and ammonium carbonate is about 10:1 to about 1:9;
- and
- b) thereafter introducing said hydrolysate into the effluent under conditions effective to reduce the nitrogen oxides concentration therein.
A process for the reduction of nitrogen oxides in a combustion effluent, the process comprising:
- a) flowing an aqueous urea solution through a conduit in operative communication with a means for introduction of a solution into the effluent;
- b) subjecting said aqueous solution of urea to heat and pressure for a time sufficient to hydrolyze at least 5% of said urea while flowing through said conduit to a hydrolysate comprising a complex of ammonium carbamate with ammonium bicarbonate and ammonium carbonate, where the ratio of ammonium carbamate to ammonium bicarbonate and ammonium carbonate is about 10:1 to about 1:9;
- and
- c) introducing said hydrolysate into the effluent by said introduction means under conditions effective to reduce the nitrogen oxides concentration therein.
1 more element
Dependencies are inferred from the claim text.